The Star Trek Report chronicles the history of mankind's attempt to reach the stars, from the fiction that gave birth to the dreams, to the real-life heroes who have turned those dreams into reality.



Monday, December 13, 2010

13 Dec 2010, Aviation Week: SpaceX Sees ISS Meet-up in 2011

SpaceX Sees ISS Meet-up in 2011
With two near-perfect Falcon 9 launches and the successful orbital operation, reentry and parachute landing of its first Dragon capsule, Space Exploration Technologies is confident it will join Russian, European and Japanese cargo ships in reaching the International Space Station next year, a critical component of NASA’s plan to maintain a six-person crew after the space shuttles are retired.

Buoyed by Dragon’s debut flight, the first under NASA’s Commercial Orbital Transportation Services (COTS)program, an elated Elon Musk, chief executive and chief technical officer for SpaceX, said he will ask NASA to combine objectives laid out for the remaining two COTS missions, for which NASA is contributing $287 million, and permit a docking at the station during its next flight, targeted for mid-2011. If successful, SpaceX would be ready to begin station cargo runs, under a separate 12-flight, $1.6-billion NASA launch services contract, before the end of 2011.

“I feel highly confident that we can go to the space station on our next flight and that we can do so by approximately the middle of next year. It’s really a relatively small delta between this vehicle and the one that will go to station,” Musk said.

“We’ll certainly give it good consideration,” echoed Alan Lindenmoyer, NASA manager of the Commercial Crew and Cargo Program Office at the Johnson Space Center. Their comments followed the Dec. 8 orbital debut of Dragon, a 3-hr., 19-min. mission Musk termed “mind-blowingly awesome.”

The 157.8-ft.-tall Falcon 9 lifted off at 10:43 a.m. EST after a day’s delay to repair two cracks in the upper-stage engine nozzle extension spotted in closeout photos on Dec. 6. The rocket was lowered into a horizontal position for visual inspections and, within hours of finding the problem, a repair that was sure to raise some eyebrows was underway: a technician cut off the lower 4 ft. of the 9-ft.-long niobium alloy sheet nozzle using aircraft metal shears. The nozzle increases the performance of the upper-stage Merlin engine and was not needed to put Dragon into a planned 300-km. (186-mi.) circular orbit for its trial run. “The second stage went up to 11,000 km.—and that’s with the shortie skirt,” Musk said.

Simulations, analysis, a quick determination of root cause—fluttering produced by a nitrogen purge venting onto the thin nozzle—and the addition of a diffuser to the vent line to prevent additional problems settled any questions about whether the unorthodox repair would jeopardize the mission, and SpaceX was cleared for a launch attempt a day earlier than originally thought possible.

Dragon flew two orbits around the planet, executing a pre-programmed series of maneuvers and systems checks that would be needed for an ISS rendezvous and docking. Then, as Dragon soared over Australia, the spacecraft fired four of its 18 Draco thrusters for 6 min. to de-orbit and plunge back into the atmosphere on a 12-deg. angle of attack. Drogue chutes, then three main parachutes, released on time, slowing Dragon to an 8-mps. (26-fps.) landing speed and a dead-on splashdown in the Pacific Ocean 500 mi. west of Baja California, completing the first FAA-licensed commercial spacecraft reentry and earning SpaceX a page in the history books of private spaceflight. “Drogue deploy and main chute deploy were the riskiest points in the mission, so when those main chutes came out, it was a done deal,” Musk said.

Future versions of Dragon will have a propulsive landing system, with parachutes as backup, he added. “You can literally land on something the size of a helipad, refuel and take off again. That will be the next-generation Dragon.”

Musk expects Dragon’s early success will bolster his company’s pitch for NASA Commercial Crew Development (CCDev) funding to work on a launch escape system, the major upgrade to transform the capsule from cargo carrier to human spaceship. With that, along with seats, solar panels and what Musk called “minor upgrades,” Dragon can “easily transport people,” he said.

“People sometimes think that to take a cargo spacecraft and put a crew into it requires this enormous amount of magical pixie dust or something. This is not at all the case. If there had been people sitting in the Dragon capsule today, they would have had a very nice ride. They would have experienced maybe up to 4.5g, about what you’d see in an amusement park, and they would have done quite well,” Musk said.

Proposals for the next round of CCDev funding are due Dec. 13, with awards expected in March 2011. NASA expects to have about $200 million for Round 2 of the program. Its initial $50 million—paid with American Recovery and Reinvestment Act funds—went to Sierra Nevada Corp. ($20 million), Boeing ($18 million), United Launch Alliance ($6.7 million), Blue Origin ($3.7 million) and Paragon Space Development Corp. ($1.4 million). The program is modeled on the COTS effort that backs SpaceX as well as Orbital Sciences Corp., which plans to debut its Taurus 4 rocket in 2011.

Before Dragon’s flight, SpaceX had received $253 million for meeting 17 of its program’s 22 milestones. Lindenmoyer said another $5 million would be forthcoming if post-flight review supports the mission’s apparent success.

“Getting this far this fast has been a remarkable achievement,” noted Phil McAlister, acting director of NASA Commercial Space Flight Development. “It’s almost unbelievable that we would get this far for less than a $300-million development effort in four years.”

SpaceX has spent more than $600 million of its own funds for Falcon and Dragon development, added President Gwynne Shotwell and, more significantly, is on the hook to cover any unexpected expenses in its quest for more affordable access to space. “If we overrun this program, we have to come up with the money through investment to cover the cost, which is dramatically different from taxpayers funding cost-type contracts where, if the contractor overruns, taxpayers have to pay the overruns. That is not the case for this program,” Shotwell said. “I think that’s exactly why this program was set up that way—to limit the government’s exposure.”

No comments:

Post a Comment